Shell

Because the individual station can not guarantee higher availability, there may be data easy problems, so it is necessary to achieve backup database needs, so I found some information on the Internet, combined with my actual situation, through the

Today, to use the shell to do some auxiliary work, long time not to use, a little forgotten ...Here's a summary of today:1. If the brackets of the If judgment to leave enough spacesuch as if space [space content space];then........Fi2. The condition

Functions are the essence of the shell, and with functions and libraries, the shell handles complex problems as well as the compiler language, gravitated the importance of shell functions and libraries.1 Definition of functionRecommended UseHow to

Shell Script (iv)(7) TR command#实现字符转换功能#-c string: Inverse string character set, that is, all character sets except for the string#-d string: Delete all occurrences of characters in string#-s: Deletes all occurrences of a sequence of characters,

Test file cat >testjasonjasonjasonfffffPress CTR + D to save1, Sort-usort -u testfffffjason2, UniqUniq TestjasonfffffjasonThis shows that Uniq needs to be sorted before it can be re-3, sort, pipe and uniq combined use Remove duplicates

Case Flow control:Case structures are used for condition judgments in a variety of situations. Similar to switch/case statements in other programming languages, but it is very different from the grammatical form.Case string inModeStatement;;Mode 2 |

A variable definition1 explicitly defined variable=xxx no spaces2 Read variable ReadingThe following two lines of code are written, reading name and namefamilyRead-p "Please input your name:" NameRead-p "Please input your whole name:" Name familyRun

When we are learning some frameworks, we usually invoke a script when we start the framework, and pass some parameters to the script, and the script will do different things depending on the parameters we pass, and the parameters we pass are the

determine if a string is empty inside the shell Category: Linux shell2011-12-28 23:18 15371 people read reviews (0) favorite report ShellThere are several main ways to do this:echo "$str" |awk ' {print length ($)} 'Expr Length "$str"echo "$str"

The shell has conditional test statements, which are usually done using the test command or the [] command, which is the basis of the conditional Judgment statement If~then statement, especially the [] command. Let's explain some of the conditional

Check if the remote port is open for bash: NC-nvv $IP $PORTtelnet $IP $PORT Front and back switch for current task: Ctrl + ZFG The first 5 characters of the Intercept variable: ${variable:0:5} SSH Debug

Select is also a kind of loop, it is more suitable for use in the case of user choice.For example, we have one such requirement, after running the script, let the user go to select the number, select 1, run the W command, select the 2 run Top

Business background: Let a.sh and b.sh execute simultaneously, not sequentially Solution: S.SH is responsible for dispatching a.sh and b.sh. The code is as follows:s.sh#!/bin/bashsource/etc/profile;date= ' 2015-05-06 '

Pattern of 1.AWKBEGINENDexpression Example: nf>10 or/^a//regular expression/?You can use a/^a/like this.Another way of writing $ ~/^a///Field matchBetween expressions you can use && | | !?: Operators do Boolean operations (which can be regular

NOTES: # Note: The # in #!/bin/bash at the beginning of the shell file is not a comment run: 1, bash shell.sh 2, chmod +x shell.sh./shell.sh 3, add to Path change Amount of 4,. ./shell.sh Troubleshooting: 1, syntax error when running with prompt 2,

Loops in a loop shell are mainly for,while,untile,select for 1, list for loop for VARIABLE in (list) do Command Done example: Loop print John's favorite fruit for fruit in apple orange banana pear Do echo "$fruit is John's

First, the file code"Steering" means that the standard input (such as the keyboard) should be read by other files, and the result should be displayed on standard output (such as screen) and output to other files. The concept of file descriptor is

One, for loop The For loop works by taking the serial element one by one out, putting it into the specified variable sequentially, and repeating the contained command area (between do and done) until all the elements takeUntil the end. Where serial

1. Enter the HBase command line>hbase ShellExit command line>quit2. Create a table>create ' users ', ' user_id ', ' address ', ' info '3. View All Tables>list4. View table Structure>describe ' users '5. Delete the table:>disable ' users ' >drop '

The feature of this series of blogs is--give the results of each orderOriginally wanted to write a good process, get a picture of what, but think online analysis too much, are better, so these blog even if it is a summary of their own it.#include